Synthesis, crystal growth and characterization of Tl 3 BX 4 ‐compounds (B = V, Nb, Ta; X = S, Se)

Single crystals of Tl 3 BX 4 ‐compounds (B = V, Nb, Ta; X = S, Se) were grown by the Bridgman‐Stockbarger technique. The compounds were synthesized from the high‐purity elements. The melting points were determined by differential thermal analysis. Tl 3 VS 4 , Tl 3 TaS 4 and Tl 3 TaSe 4 yielded single crystals up to 10 cm 3 . The other compounds show single crystalline pieces up to 1 cm 3 . Infrared photographs and electron microprobe analyses revealed inclusions of TlS in the sulfur compounds, in Tl 3 VSe 4 and Tl 3 NbSe 4 inclusions of TlSe and in Tl 3 TaSe 4 small amounts of Ta.